1. Field of the Invention
The present invention relates to a novel pipetting device for inducting and discharging a liquid. More particularly, the present invention provides a novel pipetting device and method for inducting and discharging a liquid which inducts a liquid into a tip portion thereof in a specified quantity and discharges the inducted liquid from the tip portion in a predetermined quantity by way of pressure control which is corrected in response to changes in the internal pressure of the tip portion and fluctuations in the atmospheric pressure.
2. Description of the Related Art
Devices for inducting a liquid contained in a container in a specified quantity and then transferring the inducted liquid to another container are referred to as pipetting devices.
Such a pipetting device has a configuration wherein a piper portion is provided at a tip portion thereof. The tubular tip portion is dipped in liquid in a container and a negative pressure is produced in the tip portion to induct a liquid. Thereafter, the liquid in the tip portion is discharged by pressurizing the tip portion after it is moved to another container.
Such a conventional device however, suffers from the drawback that there is variation in metering accuracy due to changes in the internal pressure of the tip portion as a result of the induction of liquid and fluctuations in the atmospheric pressure which hinders stable induction of the liquid.
In other words, the internal pressure of the tip portion changes when a liquid is inducted into or discharged from the tip portion. As a result, if the volume inside the tip portion is large and a large quantity of liquid is inducted, there will be an error which is large relative to the specified quantity. The only way to reduce such an error has been to reduce the volume inside the tip portion as much as possible.
Further, the measurement error depends on the weather at the time of the measurement and, for example, an error becomes larger when a depression passes.